JP3911086B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus such as a copying machine, a printer, and a facsimile machine having an intermediate transfer member.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, each unit arrangement of an image forming apparatus using an intermediate transfer method is an abbreviation in which a sheet feeding unit is arranged at the lower part of the apparatus body and a fixing unit and a sheet discharging part are arranged at the upper part in order to shorten the conveyance path length. Some have vertical transport paths. Since the intermediate transfer member performs color superimposition on the surface before being transferred to the sheet, the intermediate transfer member itself needs to be enlarged in accordance with the increase in the size of the sheet. When it corresponds to a large size such as A3 size (297 × 420 mm) or DLT size (279 × 432 mm), it is twice as large as an intermediate transfer body for A4 size (210 × 297 mm) or LT size (216 × 279 mm). It becomes size.
[0003]
When a user replaces a replacement unit such as a jam processing or a process cartridge including an intermediate transfer member, the front casing is opened and the operation is performed. However, as described above, the corresponding paper size of the apparatus becomes large. As a result, the intermediate transfer member and the process cartridge itself that also serves as a conveyance guide are enlarged. Accordingly, the front casing that forms one of the conveyance guides is also increased accordingly, and the distance for accessing the process cartridge through the front casing when the user opens the front casing and replaces the process cartridge is increased. It will be.
[0004]
Therefore, by dividing the front case into two parts and bringing the rotation fulcrum of the first front case that comes to the user side when it is opened, that is, when opened, to the inside of the apparatus (non-moving part), The access distance can be reduced, and interference with the device (non-moving part) at that time can be prevented by changing the rotation fulcrum of the second front case, and the second front case is changed to the first front case. The thing which made the opening / closing operation | movement interlock | cooperate by energizing is proposed.
[0005]
However, in such a configuration, since the second front housing is only urged with respect to the first front housing, the second front housing can be opened and closed independently. Is located at the most accessible position, it can be easily opened during machine operation, leading to the possibility of machine malfunction.
[0006]
Therefore, the present invention allows the first front case and the second front case to be opened and closed as they are, and prevents the second front case from being opened and closed to prevent malfunction and operation. An object of the present invention is to provide a color image forming apparatus capable of reducing the cost.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the image forming apparatus according to the first aspect of the present invention has a paper feed unit disposed on the lower side of the apparatus main body and a paper discharge unit disposed on the upper side. A transfer paper conveyance path extending in a direction leading to the paper discharge unit, the apparatus main body having a non-moving part housing and a rotation center below the non-moving part housing so as to open the transfer paper conveyance path; A front housing that is rotatable, and a process cartridge that includes an intermediate transfer body that is set on the non-moving portion housing side and has an outer transfer portion that serves as one of the transfer paper conveyance paths. It is divided into the second front casing of the first front housing and the lower side, respectively rotatable by a rotation fulcrum different and these first front housing and the second front casing, the first front The rotation fulcrum of the part housing is arranged inside the stationary part housing from the rotation fulcrum of the second front housing. In the image forming apparatus, the second front housing is urged toward the first front housing, and the projection provided on the first front housing pushes the guide provided on the second front housing. As a result, the second front housing can be opened and closed in conjunction with the opening and closing operation of the first front housing, and the guide portion provided on the second front housing is connected to the projection portion of the first front housing. A first guide part that moves during the opening operation of the front housing, and a second guide part that faces the first guide part and the protrusion when the first front housing is closed and serves as a stopper for the protrusion part It is characterized by providing.
[0008]
According to the second aspect of the present invention, the first guide portion and the second guide portion are integrally formed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a sectional view showing a color image forming apparatus as an embodiment of the image forming apparatus according to the present invention. In the figure, reference numeral 1 denotes a photosensitive belt which is a belt-like image carrier, and the photosensitive belt 1 is installed between rotating rollers 2 and 3, and is rotated clockwise in the figure by driving the rotating rollers 2 and 3. Be transported. In the figure, 4 is a charging charger as charging means, 5 is a laser writing system unit as image exposure means, 6 is three developing means containing yellow, magenta and cyan color developers, that is, a rotary color developing device. Reference numeral 7 denotes a black developing device containing a black developer provided separately from the color developing device 6. The color developing unit 6 and the black developing unit 7 are each provided with a developing roller that comes close to or in contact with the photosensitive belt 1 at a predetermined position, and the electrostatic latent image on the photosensitive belt 1 formed by the laser writing unit 5 is displayed. Visualize by non-contact development or contact development.
[0010]
In the figure, reference numeral 8 denotes an intermediate transfer belt as an intermediate transfer member. The intermediate transfer belt 8 is provided between the rotating rollers 9 and 10 and is conveyed in the counterclockwise direction in the drawing by driving the rotating rollers 9 and 10. Is done. The photosensitive belt 1 and the intermediate transfer belt 8 are in contact with each other at the rotating roller 3, and the first visible image on the photosensitive belt 1 is intermediated by a bias brush 11 provided in the intermediate transfer belt 8. The image is transferred onto the transfer belt 8. The process is repeated four times if there are four colors, and the images of the respective colors are superimposed on the intermediate transfer belt 8 so that there is no color shift (primary transfer). The photosensitive member 1, the intermediate transfer belt 8 and the respective rotating rollers, the cleaning and waste toner storage box 12 for the photosensitive belt 1, and the cleaning unit 13 for the intermediate transfer belt 8 are integrated as one process cartridge.
[0011]
A sheet feeding cassette 16 and a sheet feeding roller 17 for setting the sheet 14 are disposed as a first sheet feeding unit below the main body frame 15 which is a non-moving casing. The pivotable front housing serving as one conveyance guide is composed of an upper first front frame 18 and a lower second front frame 19, and the main body frame is pivotable about a fulcrum 20 and a fulcrum 21, respectively. 15 and is fixed to the main body frame 15 by the lock lever 22 in the closed state.
[0012]
The paper 14 in the paper feed cassette 16 comes into pressure contact with the paper feed roller 17 and is fed into the apparatus by the frictional force with the paper feed roller 17. The paper 14 exiting the paper feed cassette 16 passes through the paper conveyance surface of the second front frame 19, passes through the conveyance roller pair 23, the registration roller pair 24, and enters the nip between the intermediate transfer belt 8 and the transfer roller 25. It is transported in a timely manner so that the position is correct. Due to the action of the transfer roller 25, several color toner images on the intermediate transfer belt 8 are collectively delivered, the paper 14 is sent to the fixing device 26, the toner image is fixed, and the main body frame is fixed by the paper discharge roller pair 27. 15 is discharged to the paper discharge stack unit 28 at the upper part.
[0013]
Note that the conveyance roller pair 23, the registration roller pair 24, the transfer roller, and the manual feed tray 29 as the second paper feeding means are attached to the first front frame 18, and are arranged in the first front frame 18 because of the arrangement of the rollers. It has a configuration with high positional accuracy. The manual feed tray 29 as the second paper feeding means is provided on the operator side (right side in the figure) of the first front frame 18. The manual feed tray 29 is opened from the position indicated by the two-dot chain line in FIG. 1 to the position indicated by the solid line only when used, and the sheets are stacked. The loaded paper is sent to the feed roller 31 by the contact operation of the pickup roller 30, and is conveyed to the registration roller pair 24 by the feed roller 31, and thereafter, is transferred to the paper discharge stack unit 28 through the transfer and fixing processes as described above. Discharged.
[0014]
FIG. 2 is a cross-sectional view (A) showing the first front frame 18 and the second front frame 19 of this embodiment, and an enlarged view (B) of the main part in the middle of the opening operation. A protrusion 18 a is provided at the lower part of the exterior surface of the first front frame 18, and a first guide inclined part 19 b is provided in a concave shape at the upper part of the second front frame 19. The second front frame 19 is provided with a second guide portion 19c serving as a stopper so as to surround the protrusion 18a on the upper side of the first guide inclined portion 19b.
[0015]
As shown in FIG. 2A, when the first front frame 18 and the second front frame 19 are closed, the protrusion 18a of the first front frame 18 is in the first guide inclined portion 19b of the second front frame 19. It's stuck in until you put the most. When the first front frame 18 is opened around the fulcrum 20, the protrusion 18 a of the first front frame 18 slides on the edge of the first guide inclined portion 19 b of the second front frame 19, and the second The front frame 19 is pushed down in the direction of the arrow in the figure. As a result, the interlocking opening operation of the first front frame 18 and the second front frame 19 is performed. The second front frame 19 is pulled toward the device frame 15 by a spring 32. When the first front frame 18 and the second front frame 19 are opened, the second front frame 19 is opened by its own weight (downward). It does not rotate).
[0016]
If only the second front frame 19 is to be opened alone from the state in which the first front frame 18 and the second front frame 19 are closed, the second guide portion 19c hits the protrusion 18a and cannot be opened any further. On the other hand, when only the first front frame 18 is opened, it can be opened because the projection 18a slides in the first guide portion 19b.
[0017]
Then, after opening the first front frame 18 and the second front frame 19 in conjunction with each other, as shown in FIG. 3, only the second front frame 19 can be opened alone. At this time, in order to prevent the second front frame 19 from returning in the closing direction by the spring 32, a third guide portion 19d as a second stopper hooked on the protrusion 18a is provided at the lower portion of the second front frame 19.
[0018]
【The invention's effect】
As described above, the image forming apparatus according to claim 1 divides the front housing into the first front housing and the lower second front housing, and the first front housing and the second front housing. The part housing can be opened and closed interlocked, and the guide portion of the second front housing is provided with a portion serving as a stopper for the projection of the first front housing, so that the first front housing and the second front housing are Since the second front housing cannot be opened independently in the closed state, there is an effect that the second front housing can be easily opened during the machine operation, thereby preventing the malfunction of the machine. .
[0019]
As described above, the image forming apparatus according to the second aspect is formed by integrally forming the first guide portion and the second guide portion, so that the cost can be reduced in addition to the common effect. There is an effect.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a color image forming apparatus as an embodiment of an image forming apparatus according to the present invention.
2 is a cross-sectional view (A) showing a first front frame and a second front frame in the apparatus of FIG. 1, and an enlarged view (B) of a main part in the middle of an opening operation.
3 is a cross-sectional view showing a state in which the second front frame is further opened with the first front frame and the second front frame being opened in the apparatus of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Photoconductor belt 2, 3 Rotating roller 4 Charging charger 5 Laser writing system unit 6 Rotating type color developing device 7 Black developing device 8 Intermediate transfer belt 9, 10 Rotating roller 11 Bias brush 12 Cleaning and waste toner storage box 13 Intermediate transfer belt cleaning unit 14 Paper 15 Body frame 16 Paper feed cassette 17 Paper feed roller 18 First front frame 18a Protrusion 19 Second front frame 19b First guide inclined portion 19c Second guide portion 19d Third guide portions 20, 21 Support point 22 Lock lever 23 Transport roller pair 24 Registration roller pair 25 Transfer roller 26 Fixing device 27 Paper discharge roller pair 28 Paper discharge stack part 29 Manual feed tray 30 Pickup roller 31 Feed roller 32 Spring

Claims (2)

A paper feeding unit is disposed on the lower side of the apparatus main body, a paper discharge unit is disposed on the upper side, and a transfer paper conveyance path extending in a direction from the paper feeding unit to the paper discharging unit is provided. And a front housing having a rotation center on the lower side with respect to the non-moving portion housing and rotatable so as to open the transfer paper conveyance path, and the exterior portion is set on the non-moving portion housing side. made from a process cartridge containing one to become an intermediate transfer member of the transfer sheet conveying path, said front casing is divided into the second front casing of the first front housing and the lower side of the upper side, these first The first front case and the second front case can be rotated by different rotation fulcrums, and the rotation fulcrum of the first front case is located inside the stationary part case more than the rotation fulcrum of the second front case. In the arranged image forming apparatus, the second front housing is biased toward the first front housing, The projection provided on the first front case pushes the guide provided on the second front case, so that the second front case can be opened and closed in conjunction with the opening and closing operation of the first front case. In addition, the guide portion provided on the second front housing includes a first guide portion in which the protrusion moves during the first front housing opening operation, and the first front housing when the first front housing is closed. An image forming apparatus comprising: a first guide portion; and a second guide portion that is positioned to face the protrusion and serves as a stopper for the protrusion.   2. The image forming apparatus according to claim 1, wherein the first guide part and the second guide part are integrally formed.

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